package cn.tedu.lmx.jdbc;

import java.sql.*;
import java.util.Scanner;

public class Login {
    public static void main(String[] args)throws  Exception {
        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入账号：");
        String username = scanner.nextLine();

        System.out.println("请输入密码：");
        String password = scanner.nextLine();

        loginPlus(username,password);
    }
    public static void login (String n,String p ) throws  Exception {
        System.out.println("username=" + n);
        System.out.println("password=" + p);
        //账号为' or '1'='1也能成功
        String sql = "SELECT id FROM `user` WHERE username = '"
                + n +
                "' AND `password` = MD5("
                + p + ")";
        System.out.println("得到的SQL语句是：" +sql);
        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
        String username = "root";
        String password = "root";
        Connection connection = DriverManager.getConnection(url, username, password);
        Statement statement = connection.createStatement();
        ResultSet set = statement.executeQuery(sql);

        if(set.next()) {
            System.out.println("登录成功！");
        }else{
            System.out.println("登录失败！");
        }


    }
    public static void loginPlus(String n,String p )throws  Exception {
        System.out.println("username=" + n);
        System.out.println("password=" + p);
        String sql ="SELECT id FROM `user` WHERE username = ? AND `password` = MD5(?);";

        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
        String username = "root";
        String password = "root";
        Connection connection = DriverManager.getConnection(url, username, password);

        PreparedStatement ps = connection.prepareStatement(sql);
        ps.setString(1,n);
        ps.setString(2,p);
        ResultSet set = ps.executeQuery();

        if(set.next()) {
            System.out.println("登录成功！");
        }else{
            System.out.println("登录失败！");
        }


    }
}
